Sharpener for slicing machines



Sept. 20, 1932 c. F. M. VAN BERKEL 1,873,066

SHARPENER FOR SLICING MACHINES Filed Oct. 28. 1927 lia? Patented Sept.20, 1932 UNITED STATES PATENT OFFICE CORNELIS FRANCISCUS MARIA VANBERKEL, OF WASSENAAR, NETHERLANDS, ASSIGNOR TO U. S. SLICING MACHINECOMPANY, OF LA PORTE, INDIANA, A CORPORATION OF INDIANA SHARPENER FORSLICING MACHINES Application filed October 28, 1927, Serial No. 229,339,and in Germany March 14, 1927.

This invention relates to grinders for sharpening the rotary circularknives of slicing machines and has for its object the provision of asharpener which will assist in maintaining the cutting edge of the knifein a true plane. A further object is to provide a knife sharpener whichshall be of improved construction and operation. Other objects andadvantages will appear from the following description.

The invention is exemplified in the combination and arrangement of partsshown in the accompanying drawing and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawing:

Fig. 1 is a vertical sectional view of a sharpener showing oneembodiment of the present invention;

Fig. 2 is a transverse section substantially on line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view showing a modified form of theinvention; and

Fig. 4 is an elevation of a part of the device shown in Fig. 3.

In grinding devices for the rotary knives of meat slicing machines, asheretofore constructed, the grinding elements are usually brought intoengagement with the knife by spring pressure and are maintained in engagemont with the knife also by spring pressure. In the use of this kindof grinding device. some difficulty is experienced because of the factthat the grinding device yields when the knife does not run true or isprovided with projections or depressions. Because of this tendency toyield to inequalities or irregularities of the knife, the grinder cannotbe used to remove these inequalities or irregularities. This objectionis overcome in the present invention by special arrangements whichautomatically lock the grinding elements in their operative position sothat they cannot recede from a position in which they are locked.

In the embodiment of the invention shown in the drawing, the numerals 1and 2 designate grinders for engaging the opposite sides of the knifeblade The grinder 1 is secured to a spindle 4 which is journaled in asleeve 5 having its rear end closed by an end wall 6. A ball bearing 7is interposed between the end wall 6 and the end of the spindle 4 toreceive the end thrust on the spindle. The sleeve 5 is slidably mountedin a socket 8 which is carried on a support 9 in the usual way. A spring10 urges the sleeve 5 forwardly in the socket 8. Spaced ears 11 extendbackwardly from the inner end of the sleeve 5 and a lever 12 ispivotally mounted at 13 between the ears 11. The lever 12 extendsupwardly through a slot 14 in the socket 8. A cam 15 disposedeccentrically relative to the pivot pin 13 is formed on the lever 12 inposition to bind against the inner face of the socket 8 when the upperend of the lever 12 is moved forwardly or to the left, as viewed in Fig.1.

A spring 16 normally draws the upper end of the lever 12 forwardly.Backward movement of the lever 12 about its pivot 13 is limited by ashoulder 17 on the sleeve 5. A transverse shaft 18 is provided with acam 19 arranged to engage the lever 12. The shaft 18 is rotated by ahandle 20 in a well known manner. A second cam 21 is carried by theshaft 18 in position to engage a pin 22 for operating the grinder 2 inthe usual way. The spindle 4 is retained in the sleeve 5 by balls 23which engage a groove 24 in the spindle.

When it is desired to sharpen the knife 3, the handle 20 is moved torelease the lever 12 from the cam 19. The spring 10 will move the sleeve5 forwardly to bring the grinder 1 into engagement with the knife. Atthe same time, the spring 16 will rotate the lever 12 upon its pivot 13to cause the cam 15 to engage the inner surface of the socket 8. Thiswill not interfere with the forward movement of the sleeve 5 becauseforward movement of the sleeve tends to release the cam from its bindingpressure against the interior of the socket. Backward movement of thesleeve, however, is prevented because backward movement jams the cammore tightly against the inner face of the socket 8. In this way, thegrinder is urged forwardly by the spring 10 and is locked againstbackward movement so that it will not yield to any irregularity in theknife but will retain its foremost posi tion and grind the edges of theknife to a true plane.

When the handle Q0 is again moved to cause the cam 19 to force the lever12 backwardly, the first effect will be to impart a slight rotation tothe lever 12 in a clockwise direction until the lower end of the leverbears upon the shoulder 17. Further rotation of the cam will then movethe lever 12 backwardly and carry with it the sleeve 5 and grinder 1 toremove the latter from contact with the knife.

In the form of the invention shown in Figs. 3 and 4:, the lever 12 isreplaced by an arm 25 having a perforated head 26 through which a pin 27loosely extends, the pin being threaded into the rear end of the sleeve5. A spring 28 is interposed between the head 29 of the pin 27 and theperforated head 26 of the arm 25. \Vhen the arm 25 is released by thecam 19, it will be tilted by the spring 28 so that the head 26 ams inthe socket 8 to prevent backward movement of the sleeve 5. When pressureis again exerted by the cam 19, the perforated head 26 will bear againstthe shoulder portion 29 of the pin 27 and against a stop shoulder 30 onthe sleeve 5 so that the head 26 will not jam in the socket 8 under theforce of the cam 19.

It is thus seen that operating mechanism for the grinder 1 is providedwhich permits the grinder to be moved into contact with the knife by itsoperating spring but which holds the grinder locked in its advancedposition until it is positively retracted by the oper-v ating handle andthe cam controlled thereby.

It should be particularly noted that the detent 15 shown in Fig. 1 andthe detent 26 shown in Fig. 3 each operates automatically to preventretraction of the grinder during operation while such grinder is heldresiliently against the knife by the spring 10. Therefore the wearingdown of the knife by grinding is automatically compensated for as soonas such wearing down takes place and any tendency toward irregularitiesin the knife edge is automatically counteracted by the clutch mechanismpreventing retraction of the grinder; notwithstanding the fact thatthere may be relative hard portions on the knife edge they will beground away to the same extent as the relative soft portions, because ofthe fact that the harder portions cannot move the grinder backwardly,such tendency being prevented by the clutch mechanism which is actingconstantly and automatically during all grinding operations to sharpenthe knife.

()bviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of the invention as defined by the claims hereto appended and Iwish therefore not to be restricted to the precise construction hereindisclosed.

Having thus fully disclosed an embodiment of my invention, what I desireto secure by Letters Patent of the United States is:

1. Sharpening mechanism for a slicing machine knife comprising agrinder, a detent connected with said grinder and having one position ofadjustment in which it moves freely with said grinder toward and fromsaid knife and another position in which it moves freely toward saidknife but automatically operates to prevent reverse movement of saidgrinder, and means cooperating with said detent to withdraw said grinderfrom said knife, said last-named means being arranged to hold saiddetent in its first-mentioned position of adjustment during withdrawalof said grinder.

2. Sharpening mechanism for a slicing machine knife comprising agrinder, a spindle for supporting said grinder, a spring for moving saidspindle and grinder toward the knife, an operating arm pivotally connected with said spindle, a cam lock connected with said operating arm,a spring connected with said operating arm for holding said cam lock inposition for automatically preventing reverse movement of said spindleand grinder, and means for engaging said operating arm to move said camlock out of operative position and retract said spindle and grinder.

3. Sharpening mechanism for a slicing machine knife comprising agrinder, a spindle for supporting said grinder, a journal bearing inwhich said spindle is mounted, means for holding said spindle againstlongitudinal movement in said journal bearing, a socket member in whichsaid journal hearing is slidably mounted, a spring for moving saidjournal bearing in said socket member to cause said grinder to engagethe knife, an operating arm pivotally connected with said journalbearing and having a cam detent mounted thereon, a spring for holdingsaid cam detent in position to prevent reverse movement of said ournalbearing in any position to which it is moved by said spring, anoperating handle, and means connected with said operating handle forengaging said operating arm to release said detent and thereafterretract said journal bearing, spindle and grinder.

4. Sharpening mechanism for a slicing machine knife comprising agrinder, a support for said grinder movable in the direction of the axisof rotation of said grinder toward and from the slicing machine knife, adetent connected with said support, a spring for moving said detent inone direction into a position for preventing movement of said supportfrom said knife, means for limiting the movement of said detent in theopposite direction when said detent is in inactive position, and meansfor moving said detent to said inactive position and for retracting saidsupport and grinder away from said knife.

5. Sharpening mechanism for a slicing machine knife comprising agrinder, a spring for moving the grinder into engagement with the knife,means comprising a detent for holding said grinder against reversemovement from any position to which it is moved by said spring butpermitting further forward movement of said grinder by said spring, andmeans for releasing said detent to permit withdrawal of the grinder fromthe knife.

6. Sharpening mechanism for a slicing machine knife comprising agrinder, means for moving said grinder into engagement with said knife,and an automatic one-way clutch for preventing reverse movement of thegrinder from its position in engagement with the knife but permittingfurther movement of the grinder in a direction toward said knife.

7. Sharpening mechanism for a slicing machine knife comprising agrinder, a spring acting on said grinder urging it toward said knife, anautomatic device for preventing reverse movement of the grinder in adirection away from said knife but permitting movement of the grinder ina direction toward said knife, and means for releasing said automaticdevice and then moving said grinder away from said knife.

8. Sharpening mechanism for a slicing machine knife comprising agrinder, means comprising a spindle for supportin said grinder, a springfor actuating said supporting means to move said grinder toward saidknife, a detent for preventing reverse movement of said supporting meansbut permitting forward movement thereof, a spring for operating saiddetent to its holding position, and an operating arm connected to saiddetent to release the same against the action of said last-named springto permit retraction of said supporting means and said grinder.

9. Sharpening mechanism for a slicing machine knife comprising agrinder, means for supporting said grinder for movement toward and fromthe knife, and means comprising a tiltable detent for preventing reverse movement of the grinder in a direction away from the knife butpermitting automatic movement of the grinder in a direction toward saidknife.

10. Sharpening mechanism for a slicing machine knife comprising agrinder, a spindle for supporting said grinder, a journal bearing forsaid spindle, a support for slidably supporting said journal bearing, aspring between said support and said journal bearing for moving thelatter and said spindle and said grinder in a direction toward theknife, a clutch between said journal bearing and said support forpreventing reverse movement of said journal bearing in a direction awayfrom said knife but permitting movement thereof by said spring in aforward direction, an operating arm for said clutch, a spring foractuating said arm to operate said clutch to its locking position, and amanually actuated cam for engaging said arm to release the clutchagainst the action of said last-named spring and then effect movement ofthe grinder away from the knife.

11. Sharpening mechanism for a slicing machine knife comprising agrinder, resilient means for pressing the grinder against the knifeduring operation of the latter, and automatic clutch mechanism adaptedto prevent retraction of the grinder during operation while the latteris held resiliently against said knife to automatically compensate forthe wearing down by grinding of the knife and tendency towardirregularities in the knife edge is counteracted by said clutchmechanism preventing such retraction.

12. Sharpening mechanism for a slicing machine knife comprising agrinder, mechanism supporting said grinder for movement into and out ofengagement with the knife edge to be sharpened, and clutch mechanismco-acting with said supporting mechanism to prevent movement of thegrinder away from the knife but permitting movement of the grindertoward the knife.

13. Sharpening mechanism for a slicing machine knife comprising agrinder, resilient means for pressing said grinder toward the knife,mechanism supporting said grinder for movement into and out ofengagement with the knife, and clutch mechanism co-acting with saidsupporting mechanism to automatically lock the grinder against movementin a direction away from the knife, but at the same time permits saidgrinder to move toward said knife under the influence of said spring.

14. A sharpening mechanism for slicing machine knives comprising aournal bearing, a sleeve slidably mounted in said journal bearing, agrinding spindle rotatably supported within said sleeve, means foradvancing said sleeve toward the knife which is to be sharpened, meansfor preventing reverse movement of said grinders except when it isdesired to retract said grinders comprising a cam member pivoted to saidsleeve and adapted to engage the inner surface of said bearing, meansfor tilting said cam to wedge the cam against said inner surface, anabutment on said sleeve, and mechanical means for retracting said sleevecomprising an operating element on said cam, a manually operable secondcam for operating said element to move said element about its pivot andinto engagement with said abutment.

15. A sharpening apparatus for slicing machines comprising a journalbearing having an opening extending therethrough, a sleeve slidablymounted in said opening longitudinally thereof, a grinder spindlecarried by said sleeve, a projection on the end of said sleeve extendingparallel to the longitudinal axis of said opening, a clutch loopsurrounding said projection, a spring concentrically mounted withrespect to said projection for urging said clutch loop toward saidsleeve, an abutment on said sleeve against which one side of said clutchloop abuts and about which said clutch loop is adapted to pivot underthe action of said spring to cause a wedging action between said clutchloop and said bearing which prevents movement of said sleeve away fromthe knife being ground, but permits free movement of said sleeve towardthe knife being ground, and operating means for moving said grindertoward the grinding position.

16. In a sharpening apparatus for slicing machine knives, thecombination with a bearing having a longitudinal opening therein, asleeve slidably mounted in said opening, a grinder spindle carried bysaid sleeve,a grlnding element on said spindle, a projection on one endof said sleeve within said opening, a shoulder on said projection, aclutch loop surrounding said projection and adapted to abut against saidshoulder to align said clutch loop in said opening out of bindingengagement therewith, an abutment on said sleeve adapted to co-operatewith said clutch loop and said shoulder to hold said clutch loop out ofbinding engagement with said bearing, means for moving saidclutch loopagainst said shoulder and said abutment simultaneously to permitmovement of said sleeve and grinder away from grinding position,continued movement of said last mentioned means causing the retractionof said grinder through the intermediary of said projection, clutchloop, shoulder and abutment, and a spring for normally tilting saidclutch loop to cause binding action between said clutch loop and saidbearing to prevent the retraction of said grinder from grinding positionor any movement thereof away from the grinding position during thesharpening operation.

17. A device as claimed in claim 16 in which a coiled spring surroundssaid projection and in which the projection is provided with a secondshoulder against which one end of the spring abuts, the opposite end ofthe spring abutting against the clutch loop.

In testimony whereof I have signed my name to this specification on theeleventh day of October A. D. 1927.

CORNELIS FRANCISCUS MARIA van BERKEL.

